The department's jurisdiction includes the entire city of Irvine, which covers nearly 70 square miles (180 km2) and a population of over 270,000, as well as the Orange County Great Park.

The earliest organized law enforcement in what is today the city of Irvine, would have dated back to California's entry as a US state in 1850.

The Los Angeles Sheriff's Department was responsible for law enforcement to all areas of the county at that time.

Much of its original membership came from officers that formerly had worked the Irvine area under the four-year contract with the Costa Mesa Police Department.

[3] Even after breaking away from Costa Mesa, the Irvine Police marked units continued to carry the distinct "all white" paint schemes for their cars, with a set of a green and a blue "racing stripes" running the length of the car on the driver's side, from front to back.